Process of drying cement clamps for filaments of electric lamps.



h To all it may concern: v

UNITED STATES HARRY w.- 3 mm or cnannorrnnnune cnamanjz, nssrnogi. mantra-r0 GENERAL nnncrmc comralsrYla .conronarrc g, r,

rmcass'erprw G cmann'fr cmmrsronilrrnaiann rjgi 1,024,923. No Drawing.

Be it known that I, HARRY W. Bmssrnn, a

citizen of the German Empire, residing at Charlottenburg, Germany, have invented certain new and. useful Improvements in Processes of Drying Cement Clamps for Filaments of Electric .Lamps, of which the following. is a specification. I a

My invention relates to incandescent electric lamps and comprises an improved process of treatingthe clamps of the filaments for such lamps to drive out the moisture therefrom.

As is well known, the filaments of many incandescent electric lamps are fastened to their leading-in'wires or holders by means of cement. This cement must be dried,

baked, annealed or otherwise treated to completely drive out all the moisture contained in the cement forming these clamps, before the filament is inserted in the lamp bulb. Otherwise the moisture in the cement willbe given off during thelamp exhaust ing operation and the same delayed and complicated thereby. This is especially true of metallic filaments such astungsten filaments. Heretofore, this baking or annealing has been done by applying the heatof a small jet of combustible gas, burning in the air,or by ,the heat of an electric current passed through the filament placed a reducing atmosphere. Both of these old processes have their disadvantages.- The electric treatment is expensive, especially as the work is usually done in an atmosphere of hydrogen. In the other process, the treatment of the clamps with an ordinary ggs jet, the delicate metal filament is apt to come heated-and oxidizedin the air. I have discovered that all of these difiiculties can be avoided and the baking, dr ing or annealing carried on. to-great a vantage by simply reversing the usual conditions of heating by a gas jet in an oxidizing atmosphere, and placing the filament and clamps in a reducing atmosphere of combustible gas such as hydrogen, or ordinary-illuminating gas, and then introducing a jet of air vor oxygen or oxidizing gases and igniting the Specification of ietters raten Application filed Kay 11 1909. Serial No. 495,261.

.mixture PATENT OFFICEs l-Tat f combust1ble atmosphere and oxygen or air at the pomt where said et 1s proessarily a reducing one on account of the excess of reducing gases present and the small supply of oxygen 'fed through the burner, which oxygen is consumed completely in the flame as soon as discharged from the end of the burner or tube by which it is introduced. The heat of the flame is intense and hi hlylocalized so'that' it is particularly e ective in heating a small object like the knot of cement forming a filament filament can result, no matter how much it is heated, as it isentirely immersed in a reducing atmosphere.

In all cases, of course, it is the oxygen introduced .which supports combustion whether it enters in the form of pure oxy gen or in the diluted form of ordinary air or other oxidizin mixture.

v Having, there ore, described my invention, I claim:

1. The process of heating cement clamps for lamp filaments which comprises immersing the filament and clamps in a reducing atmosphere, discharging a jet of oxidizing gas into said atmosphere adjacent to said clamps, and igniting the localized combustible mixture so formed and maintained at the point of delivery of oxygen.

2. The method of heating the joint between a filament and its holder which consists in bringing the joint into proximity to a jet of oxidizing as'burning in a reducing atmosphere in w ich the parts are immersed and thus localizing the heating effect at the joint and keeping the parts wholly under reducing conditions.

3. The method of heating a portion of an object while protecting the remainder from ing the object in an atmosphere inert with respect to said object and causing combustion between gas from said atmosphere and a gaseous jet conducted into said atmosphere in proximity to the portion of the-object to be heated.

clamp, and no possible oxidation of the' duced. The jet'of fiame so obtained is necchemical attack which consists in immers 4;. The method of heating a portion of an In witness whereof I have hereunto set my object While protecting the remainder from hand this twenty-sixth day of April 1909,. chemical attack which consists in immersin the presence of two subscribing Witnesses. 10 ing the object in an atmosphere inert with HARRY W. BRESLER. 5 respect to said object and burning a gaseous Witnesses:

jet in said atmosphere in proximity to the HENRY HAsPER, 7 portion of the object to be heated. WoLoEMAR HAUPT.

' copies of thin patent may be obtained for five cents each, b."addressing the Commissioner 5: Patents,

Washington, D. O. 

